github_pulls_create

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

Annotations already declare readOnlyHint=false and openWorldHint=true, so the mutation profile is known. The description adds genuinely non-obvious behavioral constraints beyond that: the mutual exclusivity of `title`/`issue` and the requirement that both branches pre-exist, both of which would otherwise surface only as API errors. Auth/permission requirements and side effects (notifications, draft semantics) remain undisclosed.

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 sentences, zero filler, and the operation plus its direction are front-loaded before the parameter-selection rule. Every clause carries actionable information.

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?

No output schema exists, but the return value of a PR-creation call is largely self-evident and not required here. The description covers the two real failure modes (mode selection, missing branches); it omits cross-repository/headRepo usage and draft behavior, though the schema documents those inline.

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 goes beyond the schema by asserting a cross-parameter constraint ('exactly one of the two') that the schema only expresses one-directionally as 'Required unless X', which is a useful addition for callers choosing between modes.

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 ('Open a pull request') and pins down the direction with 'from `head` into `base`'. That immediately separates it from read-only siblings like github_pulls_get and github_pulls_list, and from github_pulls_update, without needing to name them.

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 a real routing rule between two modes: supply `title` for a new PR, or `issue` to convert an existing issue, 'exactly one of the two'. It also states the precondition that both branches must already exist. It does not, however, point to any alternative tool (e.g. github_pulls_update for later edits) or state when not to use it.

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