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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds valuable behavioral context by stating it returns a plain array unlike other tools, which is beyond the annotation coverage. No contradictions.

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: first states the tool's main function, second gives a crucial behavioral distinction. No fluff, information is front-loaded and easily digestible.

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 (single parameter, no output schema), the description covers the essential purpose and return format. It could elaborate on entry structure, but annotations and the note about array vs object provide sufficient completeness for effective selection and invocation.

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 has no description for channel_id, and coverage is 0%. The description implies channel_id is the channel by saying 'the channel's EPG', but it does not clarify the type or any constraints beyond the schema. It partially compensates for the lack of schema descriptions but could be more explicit.

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?

Clearly states the tool reads the channel's EPG (what is playing/coming up). The description uses a specific verb ('Read') and resource ('EPG'), and the note about returning an array distinguishes it from siblings like get_schedule_rules.

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?

Provides clear context for when to use: to read EPG content. It contrasts return shape with other tools but does not explicitly name alternatives or state when not to use it, leaving some room for inference.

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