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

Beyond annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint), the description adds critical behavioral context: for type='company', it pulls latest 10-K data from SEC EDGAR/XBRL with correct fiscal year handling; for type='drug', it pulls FAERS counts. It also mentions results are sorted by primary metric and returns paired data with pipeworx:// citation URIs. No contradictions with 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 highly concise (under 800 characters) and front-loaded with the purpose and trigger phrases. Every sentence adds value: use case, data sources, sorting, citations, and efficiency claim. No redundant or filler content.

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 the tool has no output schema, the description adequately covers what is returned (paired data + URIs) and how results are sorted. It mentions data sources and entity types. A minor gap is not explicitly stating that the tool is read-only, but annotations already cover that. Overall, it provides sufficient context for an agent to use the tool 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 coverage is 100%, so baseline is 3. The description adds value by explaining what each type returns (company: revenue, net income, cash, debt; drug: adverse-event counts, FDA approvals, trials) and gives concrete examples for the values parameter (tickers/CIKs for company, drug names for drug). This provides meaningful context beyond the schema's type and array 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?

The description clearly states the tool performs side-by-side comparison of 2-5 companies or drugs in one parallel call. It uses specific verb phrases like 'Compare X and Y', 'rank these companies', and 'head to head', and distinguishes from siblings such as entity_profile by emphasizing it is preferable over sequential lookups.

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 advises 'ALWAYS PREFER over sequential single-pack lookups when comparing entities', providing a clear directive for when to use this tool. It also lists trigger examples like 'which is bigger / better / larger / more profitable' and notes it replaces 8-15 sequential lookups, guiding the agent to prefer this over multiple entity_profile calls.

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