contact.read

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

The readOnlyHint already establishes that this is a safe read, and the description adds useful context about the returned contact fields and the ID source. It does not discuss not-found behavior, permissions, or error handling, so it adds moderate but not rich behavioral context.

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?

A single tight sentence lists the returned fields first and ends with the required ID source. There is no filler, and the key information is front-loaded.

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 one-parameter read with no output schema, the description covers purpose, returned fields, and ID provenance. It is nearly complete, with only minor gaps around error or not-found behavior.

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 coverage is 0%, but the description compensates by explaining that target_id comes from contact.search. That is meaningful semantics beyond the schema's bare string type, though the expected ID format is still unspecified.

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 clearly identifies the resource and the specific fields returned (title, birthday, anniversary, relationship, address), and ties the operation to contact.search's target_id. It is distinguishable from contact.search, though it is phrased as a fragment rather than an explicit verb-led statement.

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 the correct workflow by specifying that target_id comes from contact.search, which tells an agent to search first and then read. It does not explicitly state when not to use this tool, but for a simple read the dependency guidance is clear.

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