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

Beyond the readOnlyHint/idempotentHint annotations, the description adds important operational context: the URL is short-lived and using the tool costs 300 credits. This helps the agent set user expectations and avoid unnecessary calls, though it does not mention what happens if has_excel is false or the endpoint errors.

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 compact and front-loaded: it states the purpose, cost, usage condition, required parameter, precondition, and endpoint in a few sentences without redundancy. Every sentence 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?

For a single-parameter tool with no output schema, the description is sufficient: it identifies the input source, the precondition (has_excel), the cost, and the nature of the return value (short-lived download URL). An agent has enough information to invoke 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 description coverage is 100%, and the parameter description already explains that filing_id is a numeric ID from list_filings and to check has_excel first. The tool description only repeats this information without adding new semantic detail, 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 clearly states the action: obtaining a short-lived download URL for the SEC-derived Excel attachment for one filing. This distinguishes it from sibling data-retrieval tools like get_filing_facts and get_filing_statement, which return structured data rather than a file download.

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 says to use it only when the user needs the spreadsheet, and instructs the agent to check has_excel from list_filings first. This gives clear when-to-use and preconditions, and references the sibling list_filings as the source for validation.

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