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

Annotations already declare readOnlyHint=true and destructiveHint=false. Description adds meaningful behavioral context: served from verified cache (completed scans under 180 days), honestly says so if no usable scan exists instead of guessing, and sentiment reflects public discussion volume rather than quality rankings. Could have added more about rate limits or exact source count, but annotations plus these details justify a 4.

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?

Well-proportioned, front-loaded sentence states exact use case, then report contents, then data source and cache policy, then exclusions. Every sentence adds value without repeating annotation or schema information.

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 sentiment tool with complete schema coverage and clear sibling differentiation, this is complete. Description states what report includes, cache freshness rule, behavior when no scan exists, and what it doesn't cover. No output schema exists, but the report components are described adequately.

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 covers 100% of parameters, so baseline is 3. Description adds the tool input examples ('Jasper' or 'jasper') and explains the response_format tradeoff in the schema. The description's mention of per-source breakdown and pros/cons also maps to response_format values, helping the agent pick. This exceeds the 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?

Description uses specific verb+resource: 'synthesized sentiment report from real user discussions' for a specific AI tool. Clearly distinguishes from siblings by naming check_tool_status and compare_tools as alternatives.

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?

Explicit when-to-use (user asks what people think of a tool, reputation, reviews, complaints, strengths). Explicit not-for list with named alternatives (check_tool_status for alive checks, compare_tools for head-to-head). Also covers cache staleness and honest failure behavior.

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