list_functions

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's addition of the data scope (24-hour counts, cron schedule) and its cost comparison to read_file add valuable behavioral context without contradicting 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 concise: two sentences with no fluff. The first sentence states what it lists; the second provides usage scenarios. Every sentence adds value.

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?

Given the tool's low complexity (1 parameter, no output schema, read-only), the description is sufficient. It explains what data is returned and when to use it, but could optionally mention if there are pagination limits or if the counts are real-time. However, the annotations and schema cover the basics, making this complete enough.

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 schema provides 100% coverage for the single parameter (project_id) with a clear description. The description adds no additional semantics for the parameter, but given full schema coverage, the baseline is 3; the description adds extra usage guidance that elevates it to 4.

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 specifies the exact verb 'list' and resource 'deployed API functions', detailing the fields returned (route, method, runtime tier, cron schedule, invocation/error counts), and explicitly distinguishes it from siblings like list_files or list_deployments.

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 explicit guidance on when to use this tool: 'after a fork, after picking up an unfamiliar project, or to verify a deploy registered the endpoints you expected.' It also suggests alternatives (read_file) with a cost comparison, making the usage context very clear.

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