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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint. Description adds 'Read-only. No side effects. Idempotent. US federal only. 4-hour cache' and even includes a fallback feedback mechanism for when the tool doesn't serve the user's need, providing rich behavioral context beyond annotations.

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 sufficiently detailed but not excessively long. It front-loads the purpose and then provides parameter details, usage guidance, and additional context. Every sentence adds value, though it could be slightly more concise by consolidating some redundancies.

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 3 parameters (1 required), has output schema (return fields listed), multiple siblings, the description covers all needed aspects: parameter defaults, caching behavior, source verification, fallback feedback, and alternative tool references. No gaps identified.

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 baseline is 3. Description adds examples for each parameter (e.g., 'SEC', 'cryptocurrency', '2024-01-31') and specifies defaults ('defaults to all notices', 'defaults to last 90 days'), which provides practical meaning beyond 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?

Clearly states 'Fetch recent Federal Register notices and rules for a specific agency.' Explicitly distinguishes from sibling tool 'regulatory_search_open_rulemakings' by specifying when to use that alternative. The verb 'fetch' and resource 'Federal Register notices' are specific and 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?

Provides explicit guidance: 'Use this to monitor recent regulatory activity for an agency. Use regulatory_search_open_rulemakings instead when filtering by topic across all agencies.' Also notes US federal only, verified source, and 4-hour cache, giving agents clear context for appropriate use.

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