update_pipeline_variable

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states this is an update operation, implying mutation, but doesn't disclose important behavioral traits like whether this requires specific permissions, if changes are reversible, what happens on failure, or rate limits. The mention of 'Returns: Updated variable info' hints at output but lacks detail about format or error conditions.

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 with a clear purpose statement followed by parameter documentation and return information. Every sentence serves a purpose with minimal waste. The parameter documentation is appropriately brief given the straightforward nature of the parameters. It could be slightly more front-loaded with usage context, but overall maintains good conciseness.

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 3 parameters, 0% schema description coverage, no annotations, and no output schema, the description is incomplete. While it documents parameters and return concept, it lacks crucial context about permissions, error handling, side effects, and what 'Updated variable info' actually contains. The agent would need to guess about important behavioral aspects of this write operation.

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 0%, so the schema provides no parameter documentation. The description compensates by listing all three parameters with brief explanations: 'repo_slug: Repository slug', 'variable_uuid: Variable UUID (from list_pipeline_variables)', and 'value: New variable value'. This adds meaningful semantics beyond the bare schema, particularly the source hint for variable_uuid, but doesn't provide format details, constraints, or examples.

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 action ('Update') and resource ('pipeline variable's value'), making the purpose immediately understandable. It distinguishes itself from sibling tools like 'create_pipeline_variable' and 'delete_pipeline_variable' by focusing on modification rather than creation or deletion. However, it doesn't explicitly differentiate from other update tools like 'update_group_permission' or 'update_repository' beyond the resource type.

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 no guidance on when to use this tool versus alternatives. It mentions that 'variable_uuid' comes from 'list_pipeline_variables', which is helpful for parameter sourcing, but doesn't specify prerequisites like needing existing variables or appropriate permissions. There's no mention of when not to use it or what happens if the variable doesn't exist.

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