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

Annotations only declare readOnlyHint and openWorldHint, yet the description discloses result cardinality (up to 5 matches), what each match carries (live availability, brands), the presence of a 'guidance' line the agent should follow, and a disambiguation policy. This is substantial behavioral context an agent could not infer from the annotations alone.

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?

Four tight sentences with the purpose front-loaded, followed by return shape, the disambiguation rule, and the cross-brand scoping note. No sentence is redundant with the schema or annotations, and each adds a distinct actionable fact.

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 carries the burden of describing returns and does so: match count cap, availability, brands, and the guidance line. Combined with the explicit disambiguation instruction, an agent has everything needed to select and invoke this tool 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?

There is one parameter with 100% schema description coverage, so the schema already documents that `query` accepts a name/display-name/email fragment. The description restates this rather than adding syntax, normalization, or matching behavior beyond what the schema provides, making the baseline 3 appropriate.

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 ('Look up an engineer (a resource) by any fragment of their name or email address'), and the parenthetical disambiguates 'resource' as an engineer versus the customer/project resources handled by sibling find tools. An agent can distinguish it from find_customer and find_project without reading any schema.

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?

Gives a clear usage condition (lookup by name/email fragment) and an explicit decision rule for ambiguous results: ask the user, never pick one yourself. It does not explicitly name when to prefer a sibling tool (e.g. find_customer for non-engineers), so it falls just short of the 5 bar.

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