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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds context by enumerating the coverage dimensions and describing output types (counts vs. per-ticker flags), which goes beyond the structured fields. It does not contradict annotations and provides useful clarity about what the call returns.

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?

Two concise sentences, front-loaded with the core purpose. The first sentence names the tool's function, the second explains the two modes. No filler or redundant repetition of the schema/annotations.

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 an output schema exists, parameter count of 1, and clear annotations, the description covers all necessary information: both invocation modes and the relevant coverage categories. The tool's behavior is fully specified for an AI agent to select and invoke it 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?

The input schema fully describes the single 'ticker' parameter with omit instructions. The description adds semantic meaning by explaining that a ticker yields 'multi-dimensional coverage flags' and listing the specific dimensions. This enhances understanding beyond the schema's basic usage note.

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 clearly states verb+resource: 'Coverage discovery.' It specifies two distinct behaviors based on presence of ticker, and names concrete data dimensions (forensic dilution, market data, news, SEC filings). This distinguishes it from sibling tools like snacs_coverage_list by focusing on coverage flags rather than list semantics.

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 implies usage by describing two modes (with/without ticker) but does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions. Sibling 'snacs_coverage_list' exists but no differentiation is provided, so the agent might conflate the two.

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