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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint, covering safety and idempotency. The description adds that archives are used 'closest to the same date', which is useful context about data sourcing, but doesn't elaborate on rate limits, response structure, or error handling.

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?

Single concise sentence that front-loads the core action and includes key constraints (2-8 competitors, same date). No wasted words.

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 annotations and a full schema with output schema, the description is largely complete. It could mention alternatives or usage context, but the essential information for calling the tool correctly is present.

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 100%, so parameters are fully documented in the schema. The description adds nothing beyond what's in the schema, so baseline 3 applies.

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 action (compares prices side by side) and resource (competitors' pricing pages). However, it doesn't distinguish itself from siblings like compare_pricing – the name 'compare_competitors' and description imply a similar function but no explicit differentiation is provided.

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?

No indication of when to use this tool versus alternatives like compare_pricing or pricing_snapshots. The description merely states what it does, leaving selection criteria unclear.

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 readOnly, idempotent, openWorld and non-destructive, so safety is covered without description help. The description adds that the result is a structured before/after diff (prices, plans, additions/removals), which is useful, but does not discuss the archived-snapshot fallback beyond what the schema already states.

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 sentence, front-loaded with the core action and followed by the concrete return content. Zero filler; every clause earns 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?

With an output schema present and 100% param coverage, the definition supplies everything needed to invoke the tool correctly and even previews the comparison result. The only shortfall is the absence of guidance on how it relates to sibling comparison/list tools.

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 date formats, the 'latest' keyword, the default date_b and the url example are all documented in the schema. The description adds no parameter-level syntax or constraints beyond that, so the baseline 3 applies.

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 (Compare) and resource (one pricing page at two dates) and enumerates the outputs: prices and plans on each date plus additions/removals. An agent can distinguish this from pricing_at or pricing_timeline, which target a single point or series rather than a two-date diff.

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 two-date framing implies when to reach for it, but there is no explicit when-not guidance and no sibling is named as an alternative. An agent must infer the selection criteria from context rather than reading it in the description.

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, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful behavioral context beyond annotations: it discloses that the tool returns historical archival data closest to a date, and that results include plan guesses, billing hints, context, and surrounding page text.

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, front-loaded sentence that immediately states the core operation before elaborating on returned content. It is efficient with no filler, though the dense colon-separated clauses could be slightly clearer if split.

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 tool has full schema coverage, an output schema, and rich annotations, so the description need not cover return values or safety in depth. It completes the picture with archival semantics and expected output content, missing only secondary details such as rate limits or authentication requirements.

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 url, date, max_text_chars, and response_format thoroughly. The description adds only high-level meaning ('as archived closest to a date' and 'page text around the prices') without detailed syntax or constraints beyond what the schema provides, so the baseline of 3 is appropriate.

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 states a specific verb and resource: extracting prices from a pricing page as archived closest to a given date, including plan guesses and surrounding page text. This is more specific than a generic retrieval tool, though it does not explicitly name a sibling like pricing_timeline or compare_pricing as an alternative.

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?

There is no explicit guidance on when to use this tool versus pricing_snapshots, pricing_timeline, compare_pricing, or compare_competitors. The phrase 'as archived closest to a date' implies a point-in-time use case, but the description never states when this is preferable or when it should be avoided.

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 readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds useful behavioral context about archive granularity (one capture per month/year), but says nothing about ordering, pagination, or result volume for a potentially long history.

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 tight sentences, purpose first, routing second. Every clause earns its place with no redundancy against the title or schema.

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?

An output schema exists, so return-value shape needn't be described, and the safety profile is covered by annotations. The description covers purpose and routing well, with only minor gaps around result ordering or size.

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 url, per, from_year, to_year, and response_format with examples. The description adds only the month/year granularity notion, which the `per` parameter description already conveys, so no meaningful lift beyond baseline.

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: listing Wayback Machine archive dates for a page, with granularity (one per month or year) called out. It clearly distinguishes itself from pricing_at by framing itself as the date-selection step. An agent can tell what it returns without opening the schema.

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?

Explicitly names a use case ('see how far back history goes') and routes to a sibling ('pick dates for pricing_at'). It lacks any when-not-to-use or mention of the other siblings like pricing_timeline, so it stops just short of the top score.

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 readOnly, idempotent, non-destructive and open-world, so safety is covered. The description adds real behavioral context the annotations lack: it reads `points` archived copies across the range, groups identical price sets into periods, and reports additions/removals – telling the agent what the call actually does and roughly what it returns.

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 tight sentences with the purpose front-loaded and the mechanism second; no filler, no repetition of the name or schema fields beyond what is needed for orientation.

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, the description needn't detail return values, and it still sketches the output shape (periods, added/removed). For a 5-parameter read tool the coverage is nearly complete, with the only gap being any hint of cost/latency tradeoffs beyond the points note.

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 every parameter (url, points, from_year, to_year, response_format) is already documented with examples and constraints. The description restates the `points` sampling behavior ('more = slower') which the schema already conveys, adding no new semantics.

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 resource (a pricing page's prices) and the temporal scope (changed over the years), so the agent can distinguish it from a point-in-time tool. However it never names or contrasts the siblings pricing_snapshots, pricing_at, or compare_pricing, leaving the timeline/at-a-moment distinction to be inferred.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no sibling alternative is mentioned. The second sentence explains the mechanism (reads archived copies, groups into periods) rather than telling the agent when this tool is the right choice over pricing_at or pricing_snapshots.

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