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' in the description is largely redundant. The genuinely additive content is the contact entity definition and the note that filtering applies to name/email, but there is no word on result volume, pagination, or ordering — the behaviors an agent would most want to know for a listing call.

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 short, front-loaded sentences with no filler; scope comes first, the parameter second, and the entity disambiguation last. The only near-waste is repeating the read-only property that the annotations already assert.

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 zero-required-param, single-filter read tool with annotations covering its safety profile, the description covers selection and filtering adequately. With no output schema present, however, it says nothing about what a returned contact looks like or how many come back, which leaves an agent guessing about the response.

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 0% — the single 'query' property is documented only as a string — so the description must carry the meaning, and it does: 'query' filters by name and email. It stops short of match semantics (substring vs exact, case sensitivity) or what happens when omitted, which is the one remaining gap for the only parameter.

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 pair (list/search) on a specific resource (the caller's company contacts from the ERP), and the closing sentence delimits the entity as a person (supplier/partner/customer) rather than a sales lead. That implicitly separates it from contact tools scoped to personal or marketing lists, though no sibling is named outright.

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?

Usage is implied: call it to enumerate contacts, add 'query' to narrow by name/email, and it is read-only so it is safe to call freely. The 'not tied to a sales lead' clause is a light when-not hint, but nothing tells the agent what to use instead for personal or marketing contacts, or what to do when the list is large.

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