update_contact

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

Description adds behavioral context beyond annotations by noting that specifying a phone enables 2FA via SMS. It also clarifies the scope as 'additional contact' (not primary), which is not in annotations. No contradiction with readOnlyHint=false or destructiveHint=false.

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 a single, front-loaded sentence that lists the purpose and a key side-effect with no redundant details. It is appropriately sized and structured for quick parsing.

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 an update tool with full schema coverage and no output schema, the description covers the main action and a critical side-effect (2FA). It doesn't mention required confirmation or error conditions, but those are documented in the schema; overall it is sufficient for an agent to understand the operation.

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 baseline is 3. The description reiterates email, password, and phone but adds no new meaning beyond the schema, except confirming the phone's 2FA behavior which is already in the schema description.

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?

Description states 'Изменить дополнительный контакт' (update additional contact) and lists affected fields (email, password, phone). This clearly distinguishes it from sibling tools like add_contact or delete_contact, making the operation unambiguous.

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?

No explicit guidance on when to use this tool versus alternatives like add_contact or update_billing_client. The usage is implied as an update for existing contacts, but no exclusions or prerequisites are stated.

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