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

Annotations already declare idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds that the operation is an upsert ('Create or update') and that it returns crm_company_id values, which explains key behavioral outcomes. It doesn't cover error cases or auth, but with annotation coverage the bar is met.

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?

The description is three sentences with zero fluff. It front-loads the action and resource, then adds return-value and workflow context. 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 tool with no output schema, the description is nearly complete: it names the resource, the input source, the return values, and the follow-up tool. The only minor gap is not explicitly stating the array nature or limits, but those are in the schema. Overall it gives an agent enough to call 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 0%, so the description must compensate. It refers to 'stored prospect companies' and mentions 'prospect_company_id' in the workflow, which tells the agent these are internal identifiers from a store. However, it doesn't explicitly describe the parameter type, format, or constraints beyond what the schema already shows, so it only partially compensates for the coverage gap.

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 opens with a specific verb and resource: 'Create or update CRM company records from stored prospect companies.' This clearly differentiates it from sibling tools like add_contacts_to_campaign or upsert_linkedin_contact, and the mention of returning crm_company_id values further clarifies its role.

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 provides clear workflow context: 'The company can exist in CRM before any contact is known; later pass prospect_company_id to upsert_linkedin_contact to link a found employee.' This tells the agent when to use this tool and points to a specific sibling for a follow-up action. It lacks explicit exclusions or alternative conditions, but the guidance is strong enough.

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