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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the underlying endpoint (GET /api/4/customers) but no further behavioral context such as default page size behavior, auth requirements, or result limits beyond a bare endpoint reference.

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?

One compact sentence front-loads the purpose and the filter options, followed by a short endpoint citation. It is appropriately sized, though the raw endpoint string is marginal value for an agent.

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 an 8-parameter, all-optional list tool with a fully documented schema and no output schema, the description is sufficient: filters and search modes are surfaced and the schema covers the rest. Minor gaps remain around pagination defaults and auth, but nothing critical blocks correct invocation.

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 description coverage is 100%, so every parameter is already documented, including exact-match semantics for 'email', free-text for 'q', and descending sort syntax. The description only summarizes the same filtering surface, adding no meaning beyond the schema, so the 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 ('List customers') plus the filtering surface (name/email search, email/tag/archived filters). It reads clearly against the get_customer/create_customer siblings, though it doesn't name any of them explicitly to reinforce the distinction.

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?

It implies when to use it by describing the optional search/filter modes, which helps an agent pick the right query. But there is no explicit when-not guidance, no mention of alternatives (e.g., get_customer for a single record), and no statement of prerequisites.

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