update_contact

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It states that the tool updates a contact and returns the updated contact, but it does not explain partial-update semantics: are omitted fields left unchanged or set to null? It also omits permissions, validation, and error behavior, which is important for a mutation tool.

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 front-loaded with the purpose, then organizes parameters in an Args block and ends with a Returns line. It is compact for a 10-parameter tool and contains no fluff. It loses a point because several parameter lines are mechanical restatements of the schema property names.

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?

This is a 10-parameter mutation tool with no annotations and no schema descriptions. Although an output schema exists, the description still leaves critical invocation details unclear: what happens to omitted fields, what shape email/phone objects must have, and how to distinguish this tool from create_contact/delete_contact. An agent could make a basic call, but not reliably a correct one in ambiguous cases.

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 for the schema's silence. It does list all 10 parameters, but most entries merely restate the schema titles with a 'New' prefix. The nested contact_emails and contact_phones parameters lack any object shape or field guidance, which is a meaningful 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 opening sentence is specific: 'Update an existing contact in IT Glue.' It names the verb and resource clearly, and the word 'existing' hints that this is not the create tool. However, it never explicitly contrasts with sibling tools like create_contact or delete_contact, so it stops short of full sibling differentiation.

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 implies the usage context: use this when you need to update an existing contact. The word 'existing' is a mild condition that separates it from creating a contact. But it provides no explicit guidance about alternatives, such as using create_contact for new contacts or get_contact/search_contacts for reads.

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