phone_flow_info

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

Beyond the readOnlyHint annotation, the description discloses that invalid or missing ids return an error 'without running or downloading anything', that placeholders are shown but runtime values are not, and that the caller should verify app, locale, verification and side effects before execution. That is meaningful behavioral context an agent cannot get from annotations alone.

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?

Front-loaded with the core purpose and return contents, then the id constraint, then failure behavior and siblings. It is dense with multiple clauses per sentence, but virtually every clause carries actionable information, so little is wasted.

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?

Covers the gap left by the absent output schema by describing what is returned (metadata, declared inputs, step templates with placeholders) and what is not. Format constraints, error behavior, and workflow position are all present, so an agent has enough to call it correctly.

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 coverage is 100%, so both parameters are already documented. The description adds real value beyond the schema by specifying the id format ('exactly two lowercase app/flow slugs, not a local file path') and giving a concrete example, though it says nothing extra about the instance parameter.

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?

States a specific verb and resource ('Inspect an installed flow') and immediately enumerates what it returns ('metadata, declared inputs and step templates') plus what it explicitly does not return ('never runtime input values'). It is clearly distinguished from siblings phone_flow_run (which executes), phone_flow_list (which enumerates), and phone_flow_update (which populates the registry).

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?

Explicitly prescribes the precondition ('Use an id from phone_flow_list'), names alternatives with their conditions ('use phone_flow_update if the registry store is empty', 'validate its file instead of guessing a registry id' for local drafts). It also states the purpose in the workflow ('before phone_flow_run').

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