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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: it names the response fields (id, channel, full name, email, phone) and the underlying GET /contacts endpoint. It omits any note on result caps or pagination behavior, keeping it short of a 5.

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 tight sentences: capability first, then return shape and endpoint. Zero padding and nothing important buried.

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?

With no output schema, the description compensates by listing the returned fields, and annotations carry the safety profile while the schema handles pagination and limits. It is nearly sufficient; only the interaction between the free-text 'query' and the specific filters is left unstated.

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 in the schema with types and bounds. The description only restates the filter categories and adds nothing on semantics (e.g. whether filters AND together, or how query differs from the field-specific filters). Baseline 3 is correct.

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 concrete verb plus resource: search the helpdesk's contacts/customers, and even enumerates the fields returned. This cleanly separates it from the sibling list_* tools (tickets, users, channels, tags), though it uses 'search' where the name says 'list', a minor wobble.

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 usage by naming the filter dimensions (free text, email, name, phone, consumer id), which tells the agent this is the lookup entry point for contacts. It gives no when-not guidance, no mention of combining filters, and no references to related tools, so usage is only implied.

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