Atlassian Bitbucket MCP Server

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

With no annotations provided, the description carries full burden and does well by disclosing key behavioral traits: it specifies that at least one field must be provided (a validation constraint), mentions Markdown support for the description parameter, describes the return format ('formatted Markdown'), and states authentication requirements ('Requires Bitbucket credentials with write permissions'). It doesn't mention rate limits or error conditions, but covers most essential operational aspects.

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 efficiently structured in three sentences that each serve distinct purposes: first states the core action and scope, second covers parameter behavior and constraints, third addresses authentication and return format. There's no wasted text, and key information is front-loaded with the primary function stated immediately.

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 mutation tool with no annotations and no output schema, the description provides good contextual completeness: it covers the action, parameters, constraints, authentication requirements, and return format. The main gap is lack of explicit error handling information or examples of what the formatted Markdown output looks like, but overall it gives the agent sufficient guidance to use the tool correctly.

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 parameters thoroughly. The description adds minimal value beyond the schema: it mentions that workspaceSlug defaults if not provided and that description accepts Markdown, but both points are already covered in the schema descriptions. The 'at least one field must be provided' constraint is useful additional semantics not in the schema, but overall parameter guidance is mostly redundant.

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 clearly states the specific action ('Updates an existing pull request'), identifies the resource ('in a repository'), and distinguishes it from siblings like bb_add_pr (which creates new pull requests) and bb_get_pr (which retrieves without modification). It specifies exactly what can be updated ('title and/or description fields'), making the purpose unambiguous.

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 provides clear context for when to use this tool: when updating an existing pull request's title or description. It mentions workspace defaults and credential requirements. However, it doesn't explicitly contrast with alternatives like bb_add_pr (for creating) or bb_approve_pr (for approval actions), leaving some sibling differentiation implicit rather than explicit.

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