protect_branch

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

Annotations already disclose destructiveHint=true and openWorldHint=true, so the bar is lowered. The description adds value beyond annotations by disclosing that the operation 'changes who may push, merge, or unprotect', 'may enable force-push or code-owner settings', requires 'maintainer-level permission', and returns 'the protection rule or a validation/permission error'. This is meaningful operational context on top of the structured annotations. No contradiction found.

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?

Two efficiently structured sentences with zero filler. Purpose is front-loaded, succeeded by usage direction, then behavioral notes. Every clause earns its place; permission requirement and return/error behavior are packed into the final sentence without bloat.

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 complex 8-parameter mutation tool with no output schema, the description covers the essentials: the operation's scope, the permission prerequisite, force-push/code-owner side effects, and the return type or error. The 'inspect first' guidance rounds out the workflow. Minor gap: it does not enumerate all side-effect flags or clarify the deprecation relationship between `name` and `branch_name`, but the schema covers parameters.

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 schema already documents all 8 parameters in detail (including access-level integer meanings and defaults). The description adds only a high-level mention of 'push/merge/unprotect access levels' and 'force-push or code-owner settings', which restates rather than extends the schema. Baseline 3 is appropriate when the schema carries the burden.

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 resource ('Protect a repository branch') with a concrete description of the effect ('set push/merge/unprotect access levels'). Explicitly names the sibling `get_protected_branch` to distinguish inspection from mutation, and the existence of `unprotect_branch` in the sibling list provides further contrast. An agent can clearly tell this tool from related ones without opening schemas.

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?

Gives explicit when-to-use guidance ('Use this to create or update protection rules for a branch or wildcard') and instructs the agent to inspect first ('use `get_protected_branch` to inspect existing rules first'). Also states the prerequisite permission ('requires maintainer-level permission'). It does not explicitly contrast with `unprotect_branch`, but the directional guidance to the sibling is strong and actionable.

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