credential_profile_set_default

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

The description adds meaningful behavioral context beyond the annotations (which already flag it as non-read-only, idempotent, non-destructive). It explicitly states what the tool does NOT do ('does not alter OS-managed secrets') and states the narrow scope ('changes only RunBeacon profile selection'), which helps the agent understand side effects and safety. No contradictions with annotations.

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 two sentences, with the first sentence front-loading the primary action and scope, and the second sentence adding a concise safety clarification. There is no repetition or filler; every clause 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?

For a simple one-parameter mutation tool with useful annotations and no output schema, the description provides sufficient context: it explains what the default affects, independence between kinds, and exclusion of OS-managed secrets. It could mention error cases or prerequisites (e.g., profile must exist), but given the schema and idempotentHint, it is reasonably complete.

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?

The single parameter 'id' is fully described in the schema with 'Existing SSH or GitHub credential profile id.' The description adds contextual meaning ('existing', 'for its kind') but does not add details beyond the schema. With 100% schema coverage, the baseline 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 uses a specific verb ('Make existing ... default') and a clear resource ('credential profile'), with the scope 'for its kind' and the clarification that SSH and GitHub defaults are independent. This unambiguously differentiates the tool from siblings like credential_profile_clear_default and credential_profile_delete.

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 clearly implies when to use this tool (to set an existing profile as default) and gives important context: SSH and GitHub defaults are independent, and it only affects RunBeacon profile selection, not OS-managed secrets. It does not explicitly name alternative tools for clearing or deleting defaults, but the usage context is clear enough for selection.

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