Buy My Agent

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

Annotations declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds valuable context: 'active listing' (implies inactive not returned), 'PUBLIC details' and 'same data an anonymous visitor sees' clarify the data scope, and 'never the private access link' explicitly discloses a key behavioral limitation. This goes beyond the annotations.

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?

The description is a single, well-structured sentence front-loaded with the verb and object. It includes all necessary caveats without redundancy, earning its place.

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 simple read operation with one parameter, annotations, and an output schema, the description fully covers what is returned (public details) and what is not (private access link). No missing behavioral or contextual information.

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?

The schema has 100% coverage with a single 'id' parameter described as 'The agent/listing id (as returned by search_agents / list_agents).' The tool description only restates 'by its id', adding no new semantic info beyond what the schema provides. Baseline 3 applies because the schema carries the burden.

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 is specific: 'Fetch one active listing's full PUBLIC details by its id' clearly states the action (fetch), resource (active listing), and scope (public details). The phrase 'never the private access link' distinguishes it from any private-detail tool, matching the sibling set.

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 description implies usage when you need full public details for a known id, and the schema parameter explicitly says the id 'as returned by search_agents / list_agents', linking to siblings. It doesn't explicitly state when not to use it, but the public/private caveat serves as a clear exclusion.

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 this a safe, read-only, idempotent operation, so the description does not need to cover destructive effects. It adds useful scope by specifying 'active listings (public cards)', which clarifies that inactive or private agents are excluded, and 'browsing' indicates a non-targeted query.

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?

The description is one sentence and front-loads the core action and object ('List active listings'). It avoids redundant restatements of the tool name or schema details, making it efficient.

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 simple read-only list tool, the description, schema, and annotations together cover the necessary information: what it returns (active public cards), how to paginate and filter (schema), and safety (annotations). It could more explicitly differentiate from search_agents, but the output schema covers return shape, so the description is largely sufficient.

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?

All three parameters (limit, offset, category) are fully described in the schema with ranges, defaults, and pagination guidance. The description adds only the phrase 'optionally filtered by category,' which is already implied by the schema, so it provides no additional semantic value beyond the 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?

The description uses the specific verb 'List' with a resource ('active listings (public cards)') and scopes it to browsing the catalogue. This clearly distinguishes from get_agent (single fetch), search_agents (search), and list_categories (category metadata).

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 phrase 'For browsing the catalogue' gives explicit context for when to use the tool. However, it does not name alternatives like search_agents or state when not to use it, so it lacks the explicit exclusion found in the highest-rated examples.

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, idempotentHint=true, and destructiveHint=false, so the safety profile is covered by structured data. The description adds context about the filter-as-companion relationship but does not reveal what the returned categories look like (structure, count, pagination). With annotations carrying the safety burden, a 3 is appropriate.

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?

A single polished sentence carrying purpose, scope, and usage guidance with zero waste. Highly front-loaded and efficient for the agent to parse.

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?

Given zero parameters and a simple enumeration purpose, the description is complete for selecting and invoking the tool. An output schema exists (though its content is not shown), which shifts the burden off the description for return-value documentation. Slightly more detail about returned category format could nudge this to 5, but it's adequately complete.

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?

The tool has 0 parameters, and the description does not need to explain any. The baseline of 4 for zero-parameter tools applies, and the description correctly stays silent since there is nothing to parameterize.

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 uses a specific verb+resource ('List the marketplace's categories') and immediately clarifies its purpose is 'for use as a filter with list_agents,' which clearly distinguishes it from sibling tools like get_agent, list_agents, and search_agents. The scope is unambiguous.

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 description explicitly states when to use this tool — as a filter companion to list_agents — which orients the agent to the integration context. It implies it is a supporting/enumeration tool rather than the primary listing, distinguishing alternatives among siblings.

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 cover readOnly/idempotent/hints, and the description adds a valuable behavioral constraint: 'public data only — never the private access link.' This goes beyond annotations and helps the agent understand data visibility and safety implications.

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 sentences, front-loaded with the main action and resource, no redundant wording. The critical privacy caveat is placed after the main purpose, keeping the description efficient.

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 an output schema present and the description covering purpose, return behavior (active listings ranked by relevance), and a key constraint (public data only), the tool is sufficiently contextualized. Pagination is inferred from the offset schema, so no major gaps.

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 100%, so the schema already documents all parameters. The description does not add meaning beyond the schema, except reinforcing that the query is natural-language based, which the schema already states.

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 uses a specific verb ('Search') and resource ('Buy My Agent marketplace catalogue') with clear scope ('by natural-language query'). It also distinguishes itself from siblings by mentioning relevance ranking and active listings, contrasting with get_agent/list_agents.

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 description clearly implies when to use the tool: when the user needs to search the catalogue by natural language. While it doesn't explicitly name alternatives or exclusions, the context is unambiguous and not misleading.

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