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

Adds meaningful context beyond the annotations: archiving is non-destructive in the sense that nothing is deleted and the contact only disappears from active lists. Combined with idempotentHint and destructiveHint=false, the agent has a clear behavioral picture; only the response/return shape is unspecified.

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 terse sentences, front-loaded with the write intent and the mode mapping, with zero redundant 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 trivial two-parameter, fully documented tool with rich annotations, this is nearly complete. The only gap is what the call returns, which is a minor omission absent an output schema.

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 coverage is 100% and both parameters are self-documented, so the schema already does the work. The description's 'is_archived true / false' mapping duplicates the schema description rather than adding new semantics, warranting the baseline 3.

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 a specific verb and mode ('WRITE: archive ... or restore'), names the resource (contact), and gives the endpoint (PATCH /contacts/{id}). It is unambiguously distinct from siblings like bukku_create_contact or bukku_get_contact.

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?

Explains the effect of archiving ('hides it from active lists; nothing is deleted'), which tells the agent when this is appropriate versus deleting. No explicit alternatives or exclusion conditions are named, so it falls short of a 5.

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