add_circle_member_channel

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

With no annotations, the description carries the full burden and does well: it discloses the 409 duplicate-channel conflict, server-side per-channel format validation, and the PROOF_API_KEY authentication requirement. It does not mention success response shape or behavior for invalid IDs, but the disclosed behaviors are the most operationally significant.

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 compact: a one-sentence purpose, one sentence for the 409 edge case, one sentence clarifying identifier formats, and an actionable access note. The purpose is front-loaded and every sentence earns its place, though the access paragraph is slightly verbose.

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 covers the most important context: auth setup, duplicate detection, and identifier validation. Gaps include what a successful call returns and how this tool relates to list_circle_member_channels, but the heavily documented schema compensates for parameter-level completeness.

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 even with no parameter info in the description. The description mostly restates the identifier format already in the schema, adding only the nuance that format is 'validated server-side,' which is marginal additional value.

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 states a specific action and resource: 'Declare a channel for a Circle member.' The 409 error detail clarifies that this is a create/register operation, which distinguishes it from list/remove siblings such as list_circle_member_channels and remove_circle_member_channel. However, it does not explicitly name any sibling, so differentiation relies on the verb choice rather than direct contrast.

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 access note ('needs a Proof account', 'Set PROOF_API_KEY and restart this server') gives a concrete precondition, and 'start_login does NOT open this tool' provides a negative usage signal. But there is no explicit guidance on when to use this versus related tools, such as checking existing channels with list_circle_member_channels before adding or using remove_circle_member_channel to change a channel.

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