list_active_sessions

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

Beyond the readOnlyHint annotation, the description adds key behavioral context: 'No API call' indicates this is a local operation with no external side effects. It also discloses the access scopes of each credential kind (e.g., portalSessions read workspaces/files/invoices, flowCredentials are weak auth scoped to a single questionnaire). This goes well beyond what annotations alone provide.

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, each earning its place. The first sentence states the purpose and the split; the second explains the provenance and the non-interchangeability. There is no filler or repetition of schema or annotation data. The off-putting but necessary 'No API call' is placed at the end, after the more important distinctions.

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 zero-parameter, no-output-schema tool, the description is complete: it identifies the exact credential types, how they are captured, and their access capabilities. It also differentiates from sibling tools without needing to enumerate those tools. Given its simplicity and the richness of the description, nothing essential is missing.

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 tool has zero parameters, and schema coverage is trivially 100%. The description compensates by clarifying what the output represents: active credentials split by kind with their derivation and limits. Since no parameters exist, the description fully satisfies any parameter-semantics needs and adds meaningful detail about the result domain.

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 verb and resource: 'List the HoneyBook credentials currently active in this MCP.' It further details the two kinds of credentials and the tools that capture them, which clearly distinguishes this from sibling listing tools. The presence of sibling names like list_projects and list_notes reinforces that this tool is specifically about credential inventory, not general data listing.

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 gives clear guidance on what the two credential types are and when they are created (use_magic_link vs use_flow_link), with a warning that they are not interchangeable. This implies when to use the tool—to inspect current active credentials and their capabilities. It lacks an explicit 'use this when' statement but the context is effectively informative.

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