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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond that: it names the upstream source (FINRA) and the specific data fields returned, which matters because there is no output schema. It omits settlement-frequency or freshness caveats, keeping it short of a 5.

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?

Three dense sentences, front-loaded with the core purpose and the returned metrics, then the disambiguation. The FINRA terms-of-use URL is defensible as an attribution/licensing note but sits awkwardly at the end and slightly dilutes the technical 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?

With no output schema, the description correctly compensates by listing the returned metrics and the data source, and it situates the tool among the short-related siblings. Nothing essential to calling it correctly is missing, though freshness/settlement timing isn't addressed.

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 both parameters (q, limit) are fully documented in the schema itself. The description's only parameter-relevant signal is that q accepts a ticker, adding nothing about accepted name formats or how limit interacts with settlement periods. Baseline 3 applies when the schema carries the burden.

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?

States a concrete verb and resource ('Look up a ticker's FINRA short interest') and enumerates the exact metrics returned: shares sold short, days-to-cover, change vs prior settlement. It explicitly separates itself from the sibling short_volume_search by naming the distinction, so an agent can route without opening either schema.

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?

Explicitly contrasts this tool with short volume ('the real short metric ... distinct from short volume which includes market-maker hedging') and suggests pairing with fails-to-deliver + short volume. That is strong disambiguation, but it stops short of stating conditions like when to prefer short_interest_squeeze or short_squeeze_candidates.

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