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

Annotations declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety profile is well covered. Description adds behavioral context beyond annotations: it clarifies data source (FINRA daily short-volume ratio), time window (~20 trading days), and billing behavior (cost $0.02 per call; unpaid calls return a payment-required error). This goes beyond the annotation set.

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?

Four concise sentences with distinct purposes: definition, disambiguation from short interest, alternative routing, and billing note. Zero filler, important caveats front-loaded.

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?

Complete for a read-only single-parameter tool: describes data source, time window, meaning, alternative, prerequisite lookup, billing, and error condition. Output schema exists, so return value documentation is not the description's job. No unresolved gaps.

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 the baseline is 3. The description adds value by explaining the cik parameter's format and providing a concrete example (320193 for Apple), plus routing guidance (call lookup_company first if only ticker/name). This enriches the schema documentation without repeating it.

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 states a specific verb-resource pair: measures short-selling pressure for one company via FINRA daily short-volume ratio over ~20 trading days as a bearish-sentiment proxy. It also distinguishes itself from the related concept of short interest explicitly, though not from sibling tools by name.

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 clear context for when to use this tool (when needing short-sale volume ratio over ~20 days, as a sentiment proxy) and explicitly recommends company_signal for short sentiment scored alongside other factors. It also notes non-investment-advice and billing prerequisites (cost per call, payment-required errors). Lacks explicit when-not-to-use or alternative distinctions beyond company_signal.

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