Pet Welcome Box – hand-picked gift ideas

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only flag readOnlyHint=false and openWorldHint=true; the description adds the auth token requirement and the mandatory marketplace/locale context, which is real added value. However, those same facts are already spelled out in the schema parameter descriptions, and nothing is said about duplicate-item handling or what happens on failure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, action front-loaded, no filler. The parenthetical requirement clause is telegraphic but never wasteful; it could have been folded into a cleaner prerequisite sentence.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 10-parameter write tool with no output schema and thin annotations, the description omits how an item is identified, whether the call is idempotent, and what is returned. The 4 required parameters are covered, but half the schema is opaque to the agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 40% across 10 parameters, so the description needs to compensate and does not. It never explains the item-identity parameters (asin, url, name, title, emoji, searchKeywords) or whether one of them must be supplied — a critical gap for a tool whose whole job is adding an item.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource — 'Add an item to an existing pet kit list' — which clearly separates it from create_wishlist (which makes a new list). It does not name any sibling explicitly, so the separation is inferred rather than stated.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The parenthetical 'requires editToken' plus 'Requires marketplace + locale' gives preconditions and implies the workflow (create first, then add), but there is no explicit 'use this instead of X when Y' guidance against resolve_product or create_wishlist.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false and openWorldHint=true; the description adds real value by naming the returned fields (id, editToken, ownerUrl, shopUrl), which tells the agent that the created list has an owner-scoped edit token and a public shop URL. It also reinforces the required inputs. It does not address idempotency, failure modes, or rate limits, but with no output schema the return-value disclosure is the meaningful addition.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the action and ending with the return contract and required inputs. Each sentence carries information the agent can act on.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The return fields compensate for the missing output schema, but with eight parameters and only 25% schema coverage, the accepted values for the six optional parameters go unexplained. An agent can call the tool with just the two required inputs but cannot reason about what petName, species, sizeBand, or kitCategories change in the created list.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 25%, so six of the eight parameters (stage, petName, species, sizeBand, budgetBand, kitCategories) are undocumented in both schema and description. The description only restates that marketplace and locale are required, which the schema already enforces via its required list and descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Create an empty pet welcome-kit list'), consistent with the title. It is clearly distinguishable from the sibling add_item, which operates on an existing list. It does not name siblings explicitly, but the create-versus-mutate distinction is implicit and clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The word 'empty' implies this is the first step before items are added, but no alternative or precondition is stated. An agent must infer that this tool precedes add_item rather than being told so.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds real value beyond that by disclosing the shape of the result and the data-quality caveat that tagConfigured may be false until real Associates IDs are configured. This 'honest search-mode' warning prevents the agent from misreading a false flag as an error.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with what is returned before the usage note and the caveat. The phrase 'Honest search-mode' is slightly jargon-ish, but it is immediately explained by the clause that follows, so nothing is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no input parameters and no output schema, the description carries the full burden of explaining the return values — and it does, listing the four keys and the meaning of the ambiguous one. An agent has everything it needs to call this and interpret the result correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Zero parameters, so there is no parameter semantics to explain and the baseline is 4. The description instead documents the returned keys, which is the more useful information for a no-arg discovery tool with no output schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('List supported Amazon storefronts') and enumerates the returned fields (id, domain, defaultLocale, tagConfigured), so the agent knows exactly what comes back. It also positions itself relative to the sibling shopping tools by telling the agent to pass the marketplace + locale values onward, which distinguishes it from search/resolve_product/add_item.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The line 'Pass marketplace + locale on shopping tools' makes the tool's role in a wider workflow clear — call this to discover valid identifiers before invoking the shopping tools. It doesn't explicitly state when not to call it or name a specific alternative, but for a zero-arg discovery tool the implied usage is strong.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-lookup profile is covered structurally. The description adds one genuinely useful non-obvious behavior: the returned URL omits ?tag= until real Associates IDs exist, which an agent would otherwise misread as a broken affiliate link. It says nothing about ambiguity handling, no-match results, or rate limits.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the capability, then the hard requirement, then the output quirk. No filler and no repetition of schema content beyond what is needed for context.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With 10 parameters, 20% schema coverage, no output schema, and only minimal annotations, the description carries substantial burden and does not meet it. Five parameters and the failure/no-match path are undocumented, which is a real risk given the tool's open-world lookup nature.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 20%, with locale and marketplace described in the schema itself. The description names ASIN, URL, keywords, marketplace, and locale, but five parameters (stage, species, sizeBand, budgetBand, kitCategory) are never mentioned anywhere, so an agent has no way to know how they affect resolution or whether they are filters or fallbacks.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb (resolve) and enumerates the accepted input forms (ASIN, Amazon URL, keywords) plus the output (buyUrl / affiliateUrl) on a chosen marketplace. That is enough to separate it from siblings like search or add_item without opening the schema, though it never explicitly contrasts itself with search, which is the closest adjacent tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Requires marketplace + locale' states the prerequisite, and the input-mode list implies the valid call shapes. But there is no guidance on when to choose this over search (e.g. resolving an already-known ASIN vs. discovering products), nor any exclusion or fallback behavior when resolution fails.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-web profile is covered. The description usefully discloses the two return shapes (PA-API products or search deep-link cards) and the odd operator note about omitting `?tag=` until real Associates IDs exist, but it says nothing about rate limits, pagination, or empty-result behavior for an open-world Amazon search.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences with the resource and scope front-loaded, and the required-input constraint placed before the alias note. The parenthetical about `?tag=` is dense but earns its place as an implementation caveat; only minor wasted phrasing.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 9-parameter, no-output-schema tool the description does compensate where it matters most: it says what comes back (products vs. deep-link cards) and confirms required inputs. The remaining gap is filter semantics for the optional facet parameters, which an agent would need in order to call it precisely.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 78%, so the schema carries most parameter meaning and the baseline of 3 applies. The description only reinforces marketplace and locale as required, and adds nothing about `stage`, `species`, `sizeBand`, `budgetBand`, or `kitCategory`, including whether those filters are strict or just ranking hints.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (search) plus the resource (pet welcome-kit / first-30-days supplies) and the scope (a specific Amazon marketplace). It also names the alias `search_kits`, which helps the agent match a sibling-looking name, but it never explicitly contrasts with `resolve_product`, which is the nearest ambiguous sibling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The prerequisite ('Requires marketplace + locale') is stated, which is real guidance. However, nothing tells the agent when to pick this over `resolve_product` (keyword search vs. known product id) or when a deep-link card is preferable to PA-API products.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.