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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds value by stating 'Factual data only' and clarifying that no recommendations or price targets are included, which is behavioral context beyond the annotations. It also specifies 'full content', though it doesn't describe the return format or error handling – but given the simple read-only nature, this is sufficient.

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 two sentences with zero waste. The first sentence front-loads the core action and enumerates the supported record types; the second sentence clarifies the data nature. Every word earns its place, and the structure is efficient and scannable.

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 single-parameter fetch tool with no output schema, the description covers all necessary aspects: the action, the input source (id from search), the types of records supported, and the nature of the data. Annotations cover the safety profile, and the schema covers the parameter. Nothing essential is missing for an agent to call it 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?

Schema coverage is 100%, so the parameter 'id' is documented as 'An id returned by search'. The description enriches this by listing what kinds of ids are valid (company profile, announcement, filing page, IPO issue), giving the agent a clearer understanding of what it can retrieve. This goes beyond the schema's minimal definition.

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 clearly states the verb 'Retrieve' and the resource 'the full content of one search result by its id', and it enumerates the specific record types (company profile, announcement, filing page, IPO issue). This differentiates it from sibling tools like search (which returns ids) and company_snapshot (which presumably targets a specific record type), making the purpose 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 implies usage: you must first have an id from search, and this tool retrieves the full content for that id. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for a one-parameter fetch tool. The lack of explicit exclusion criteria keeps it at a 4 rather than a 5.

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