update_haproxy_backend

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the description does not need to repeat these. The description adds minimal context ('existing', 'by ID') but does not disclose behavioral details such as the effect of apply_immediately, whether changes are staged, or if a reload is required. This is acceptable given the annotations cover the safety profile, but the description contributes little beyond the obvious.

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: 'Update an existing HAProxy backend by ID.' It contains no filler words, tautologies, or redundant information, and it immediately conveys the core action. Every word 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?

The tool has 7 parameters, a rich schema, annotations, and an output schema. The description is minimal but sufficient for an update tool: it identifies the target (existing backend) and the key identifier. It does not explain the apply_immediately parameter or update semantics, but those are covered by the schema's per-parameter descriptions. Overall, the description is complete enough for a moderately complex update operation, though it could benefit from a brief note about typical use cases or application behavior.

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%, with each parameter (mode, name, descr, balance, backend_id, check_type, apply_immediately) already having a clear description in the input schema. The tool description adds no additional parameter semantics, but the schema fully compensates, so the baseline score of 3 is appropriate.

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 'Update an existing HAProxy backend by ID' uses the specific verb 'Update' and clearly identifies the resource ('HAProxy backend') and the selection method ('by ID'). It distinguishes itself from sibling tools like create_haproxy_backend and delete_haproxy_backend by focusing on modifying an existing entity.

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 usage for modifying an existing HAProxy backend, but it does not explicitly state when to use this tool versus alternatives like create_haproxy_backend or delete_haproxy_backend. There is no mention of preconditions (e.g., backend must exist) or exclusions, leaving the agent to infer the appropriate context from the tool's name and sibling names.

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