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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the bar is lower; the description still adds real value by disclosing the NOT_FOUND behavior for unknown ids and for private Contacts the caller cannot see. No mention of rate limits or response envelope, but no output schema exists to lean on.

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 sentences, front-loaded with purpose, then prerequisite, then failure mode. Every sentence carries actionable information with no 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?

Since there is no output schema, listing the returned fields (including facts with sources and Deals) is essential and present. The id-sourcing prerequisite and the NOT_FOUND edge case round out what an agent needs to call this 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?

With a single required parameter at 100% schema description coverage, the schema already fully documents 'id'. The description reinforces the provenance of the value ('from search or list_contacts') but adds no format, type, or constraint details beyond the schema.

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?

Names the exact verb and resource ('Read one Contact in full, given its id') and enumerates the payload: phone, social links, research brief, facts with sources, Company, owner, Deals. This clearly separates it from the list_contacts/search siblings, which return many records.

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 search or list_contacts first to get the id' gives an explicit prerequisite and names the two alternatives for acquiring the identifier. It stops short of contrasting get_contact with get_company/get_deal, but the resource distinction is self-evident.

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