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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds only that the result is a full time series; it says nothing about pagination, limit truncation behavior, or data ordering beyond what the schema 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?

Two compact sentences with the core resource description front-loaded. The second sentence about form filtering is slightly redundant with the schema but still earns its place as a quick scoping cue.

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 read-only, five-parameter lookup with full schema coverage and no output schema, the description covers purpose, scope, and the key filter. What it lacks is any signal about result volume or ordering, which would help an agent interpret the 'time series' return.

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 all five parameters are already documented, including defaults, the limit cap of 60, and the form filter. The description's example tag format adds marginal value but does not extend parameter meaning beyond the schema 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 (full time series retrieval) and resource (one XBRL concept across any taxonomy/tag), with a concrete example (us-gaap:Revenues). It implicitly distinguishes itself from broader fact/statement siblings by scoping to a single concept, though it never names 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?

The form filter hint ('10-K or 10-Q') implies a usage context, but there is no explicit when-to-use guidance and no routing to siblings like get_company_facts or get_financial_statement. An agent must infer the boundary itself.

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