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

Annotations already cover the read-only, idempotent, non-destructive profile. The description adds useful behavioral context beyond those annotations: it returns the full field set including custom fields/owner/stage, and it targets the shared workspace rather than the global database. No contradiction.

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?

Three short sentences, each earning its place: what the tool returns, how to find the input id, and which data scope is read. Front-loaded and free of filler.

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 tool with rich annotations and an output schema, nothing critical is missing. The agent knows the id source, the workspace scope, and the returned fields. No further behavioral or safety disclosure is needed.

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?

With 100% schema description coverage, baseline is 3. The description adds practical meaning by clarifying that the parameter is an Apollo contact id and that it should be obtained via post_apollo_contacts_search. This goes beyond the schema's bare 'Contact ID' label.

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 the exact operation: retrieve one saved contact by its Apollo id. It adds meaningful specifics—the full field set including custom fields, owner, and stage—and clearly distinguishes itself from search and bulk sibling tools. No tautology.

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 an explicit prerequisite for correct use: find the id with post_apollo_contacts_search. It also scopes the data source by noting it reads the shared workspace rather than Apollo's global database. It does not enumerate every when-not condition, but the routing context is clear.

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