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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description contributes the PII flag and the underlying REST path, but says nothing about what an unknown id yields or whether the lookup is rate-limited.

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 compact sentences with the resource and scope front-loaded; nothing is padded or repeated. It reads as a terse fragment rather than a full sentence, but every token earns 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?

There is no output schema, so the description is the only place the return value could be characterized, and it says only 'One client contact' without listing fields or describing error behavior for a missing id. For a single-parameter read tool this is adequate but leaves a real gap.

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% — contact_id is typed as a positive integer with a documented description — so the schema carries the parameter semantics. The description only restates 'by id' and adds no format, source, or range guidance beyond it.

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 ('Get') and resource ('contact') scoped to a single record by id, and the parenthetical '(personal data)' signals the PII nature. It implicitly distinguishes itself from cats_list_contacts and cats_search_contacts by being id-based, but never names those siblings 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?

No statement of when to use this versus cats_list_contacts or cats_search_contacts, and no prerequisite such as 'you must already have a contact_id'. The id-scoped framing hints at usage but leaves the agent to infer the routing decision.

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