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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower; the description still adds real value by disclosing the shape and breadth of the payload (per-company records plus an aggregate coverage summary) and the data-source scope. It omits return format details such as ordering or truncation for a ~500-company list, which is the main remaining gap.

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?

Front-loaded with what the tool returns, then the when-to-use rule, then the scope definition — a sensible ordering. The opening sentence is a long comma-chained enumeration, but every clause corresponds to actual returned content rather than filler.

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?

There is no output schema, so the description carries the burden of explaining returns — and it does, listing the per-company fields and the summary block. Combined with the stated coverage domain and the 'call this first' entry-point role, an agent has everything needed to call it correctly with or without a filter.

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?

The single `query` parameter already has a full schema description covering matching fields and case-insensitivity (100% coverage). The description never mentions the optional filter, so it adds nothing beyond the schema here; baseline 3 applies.

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 specific verb and resource ('The public companies Ticker Scout covers') and enumerates exactly what each record carries (latest fiscal period, published records, predicted next SEC filing) plus a coverage summary. It also defines the scope boundary ('S&P 500 plus major foreign issuers that file with the SEC'), which no sibling tool provides.

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?

Gives explicit invocation triggers: 'Call this first when you do not know whether a company is covered, or to turn a company name into a ticker.' That's clear positive guidance, but it doesn't name an alternative (e.g. get_company when you already have a ticker), so the when-not case is left implicit.

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