getPersonByEmail

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

With no annotations provided, the description carries the full burden. It discloses the key behavioral trait: the tool returns either a unique contact or an ambiguity result with candidate IDs. This is valuable beyond the schema, which only says 'Email address to look up'. It does not mention error cases (e.g., no match) or rate limits, but the ambiguity behavior is a meaningful disclosure.

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 sentences with no wasted words. The core action is front-loaded, and the ambiguity behavior is stated concisely. Every sentence 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?

For a single-parameter lookup tool with no output schema, the description is nearly complete. It explains the two possible outcomes (unique contact or ambiguity result with candidate IDs). It does not specify what happens when no match is found, but the core behavior is sufficiently covered for an agent to invoke it 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?

Schema description coverage is 100%, so the schema already documents the email parameter. The description adds the lookup semantics (unique vs ambiguous) but does not add format or syntax details beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 uses a specific verb ('Look up') and resource ('a person by email address'), and clearly distinguishes the unique-match case from the ambiguity case. It differentiates from sibling tools like getPerson (which likely uses an ID) and searchPeopleByTag (which searches by tag), so an agent can select it correctly.

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?

The description implies when to use this tool: when you have an email address and need a person. It does not explicitly state when not to use it or name alternatives, but the unique-vs-ambiguous outcome guidance helps the agent understand the result and decide next steps. Sibling names like getPerson and searchPeopleByTag provide context, though no explicit exclusions are given.

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