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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds value beyond that by disclosing the delivered formats (XLSX, ICS, CSV) and that invalid or missing numbers are reported per item rather than failing the whole batch.

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 sentences, usage trigger front-loaded before the exclusion, no filler. The middle clause 'download XLSX, ICS and CSV with published dates' is slightly awkward phrasing but still carries real information about outputs.

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 detail is not needed, and the description covers trigger, exclusion, batch size and output formats. For a single-parameter read tool this is sufficient, with only the sibling differentiation left thin.

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?

With 100% schema description coverage on a single array parameter, the schema already documents the 1-50 cardinality, the item format and the per-item error behavior. The description's 'one to fifty numbers' restates the schema rather than adding syntax or format meaning, 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 verb and resource (look up federal register document numbers) plus the concrete outcomes it serves (regulatory digest, effective dates, comment periods). The phrase 'known document numbers' implicitly separates it from the search-oriented sibling find_federal_register_documents, but the sibling is never named.

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?

Opens with an explicit 'Use this when...' trigger listing the user intents it serves, and closes with a clear 'Do not use for unpublished agency guidance or legal advice' exclusion. It stops short of naming the alternative tool or the condition that selects it, so routing between this and find_federal_register_documents is still inferred.

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