find_contact

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 return payload (phone number and email) and, via "all or part of the name," hints at substring matching. It does not say what happens on no match or with multiple matches, so it adds modest context beyond the annotation.

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 short sentences front-load the purpose and the usage trigger, and the Args block is minimal and non-redundant. Every line contributes to invoking the tool correctly.

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 single-parameter read-only lookup with no output schema, the description covers purpose, trigger, returned fields, and matching semantics. The only real gap is behavior on no match or multiple matches, which is minor but worth noting.

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%, so the description carries the burden for the single parameter — and it does: it explains that the value may be a full or partial name and gives concrete examples ("Kuljot", "didi", "mom") that convey case-insensitive partial matching. No format or edge-case guidance (e.g. ambiguity resolution) is given.

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?

The description states a specific verb (look up) and resource (Contacts) and names the returned fields (phone number, email), so the agent knows exactly what this tool produces. It does not explicitly distinguish itself from the sibling list_contacts, which an agent could plausibly confuse it with, so it stops short of a 5.

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?

"Use this before messaging or emailing a person" gives a clear situational trigger tied to sibling tools like send_message and compose_email. It provides no exclusions or explicit pointer to list_contacts for enumerating all contacts, so the routing guidance is helpful but incomplete.

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