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

Annotations already indicate read-only, idempotent, non-destructive behavior, so the description adds meaningful extra transparency: results are 'announcement-derived items only,' claims are 'not independently confirmed,' full press-release text is not served, and coverage depends on public announcements. These caveats go beyond what annotations convey.

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 organized into Purpose, Guidelines, Limits, and Ex sections, with the core purpose stated first and every sentence serving a distinct function. It is thorough without being verbose.

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 the output schema, read-only annotations, and only four optional parameters, the description fully covers what the tool does, how to filter, when to use companion tools, what limitations exist, and how to call it with examples. No critical information is missing.

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 baseline applies. The description adds usage examples and repeats the date format, but it does not meaningfully extend the parameter-level meaning already present in the schema 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?

The description opens with a specific action and resource: 'return a chronological timeline of company announcements across the rCB industry - results, capacity, certification and delivery approvals.' This makes the tool's function unmistakable and distinguishes it from the broader lookup and article siblings.

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 Guidelines section gives explicit usage context: filter by region and date range, and use alongside query_companies when tracking capacity build-out or with query_policies when regulatory dates matter. The Limits section further clarifies when the data should not be over-interpreted, such as absence not being evidence of inactivity.

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