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

Annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint) already indicate safe read-only behavior. The description adds valuable behavioral context: it pulls latest 10-K data for companies (with proper fiscal year handling), FAERS/fda data for drugs, sorts results by primary metric, and returns 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 slightly wordy with the initial string of example phrases, but every sentence adds value. It is front-loaded with the core purpose and usage, then provides specifics. It could be trimmed slightly, but overall it is well-structured and informative.

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 no output schema, the description explains that the tool returns 'paired data + pipeworx:// citation URIs per entity' and that results are sorted. It also mentions it 'replaces 8–15 sequential lookups.' For a comparison tool handling two entity types with multiple metrics, this is very complete and aids the agent in understanding the return format and benefit.

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%, but the description adds significant meaning beyond the schema. For the 'type' parameter, it explains that 'company' pulls revenue, net income, cash, debt from SEC EDGAR/XBRL, and 'drug' pulls adverse-event counts, FDA approvals, trial counts. For 'values,' it specifies tickers/CIKs for companies and names for drugs. This enriches the bare 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?

The description clearly states the tool's purpose: 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It uses specific verbs like 'compare' and 'rank,' and distinguishes itself from sibling tools (e.g., entity_profile) by explicitly directing 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.'

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 provides explicit guidance on when to use this tool: 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.' It also gives concrete example queries ('which is bigger / better / larger') and details what each type ('company' or 'drug') retrieves, making it clear when to invoke.

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