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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so "Read only." adds nothing. The one piece of genuine added context is that display name and aliases govern which AI answers count as a mention — useful semantics, but nothing about unknown-domain behavior or result size/pagination.

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 the operation and payload, three short sentences, no filler. The trailing "Read only." is redundant with annotations and is the only sentence not earning its place.

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?

For a single-parameter read tool with full annotation coverage, the description covers purpose, scoping and the returned fields, which is enough given there is no output schema. Missing only edge-case behavior (empty list, invalid domain id).

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?

Single parameter with 100% schema coverage, so the schema already fully documents it. "for one domain" reinforces the scope but adds no format or sourcing detail beyond the schema's uuid-typed "Domain ID".

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?

Specific verb and resource ("List the competitor domains tracked for one domain") plus the exact fields returned (id, display name, aliases). It is clearly distinguishable from add-competitor/update-competitor/delete-competitor by the "List" framing, though it never names them explicitly.

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?

"tracked for one domain" implies the tool is scoped to a single domain and is the read path versus the add/update/delete siblings, but the description never states when to use it over alternatives or any prerequisite (e.g., that the domain must already exist / the id comes from list-domains).

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