ECP Query (read-only)

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description reinforces the read-only nature and adds behavioral context by listing example return categories and advising to use list_query_presets for endpoint discovery. It doesn't contradict annotations and provides additional context beyond the safety flags.

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 yet information-dense. The core action is front-loaded, followed by examples, endpoint guidance, explicit read-only note, and final routing to alternatives. Every sentence adds value with no filler or repetition, making it easy to parse quickly.

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 GET tool with 2 parameters and no output schema, the description covers purpose, usage, endpoint selection, alternatives, and the read-only guarantee. It's fully sufficient for an agent to decide when to call it and how to construct the request without additional lookup.

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%, but the description enriches meaning: it clarifies the endpoint parameter by specifying the two acceptable formats (preset names or /query/* paths) and provides a concrete usage example ('/query/apps'). This is beyond what the schema offers, making the tool easier to invoke correctly.

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 ('Run') and resource ('read-only ECP GET'), lists concrete data examples (device info, installed apps, active app, media player state), and explicitly differentiates from the sibling ecp_post by mentioning state-changing POSTs. The agent can immediately tell what this tool does and how it differs from alternatives.

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 names when to use ('go-to inspection tool'), when not to (state-changing POSTs use ecp_post), and provides an actionable pattern: pick an endpoint from list_query_presets or pass any /query/* path. Also gives a concrete example for enumerating app ids ('/query/apps'). This is fully actionable guidance.

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