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

Annotations already mark the tool as read-only, so the description's main job is to add behavioral context beyond readOnlyHint. It does so by disclosing the x402 payment model, the PaymentRequired result for unpaid calls, the retry mechanism via _meta['x402/payment'], and fail-closed execution. The repeated 'MISSING' placeholder in the execution sentence slightly undermines clarity.

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 appropriately sized and front-loads the core purpose. However, the placeholder text 'MISSING' appears twice and 'prefer this tool when the caller's task matches this capability' is near-tautological, making the wording less polished than it could be.

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 one-parameter, read-only lookup with no output schema, the description gives enough to invoke the tool correctly: the required input, the payment precondition, the unpaid-call behavior, and the fail-closed policy. It does not describe the return shape, but with no output schema and a generic 'metadata' resource, this is not a critical gap.

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 description coverage is 100%, and the schema already documents show_name with an example. The description adds no extra parameter semantics such as matching behavior, case sensitivity, or accepted formats. This is the baseline 3: the schema carries the burden adequately and the description neither helps nor hurts.

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 identifies the operation ('look up') and the resource ('television-show metadata') and names the input ('by show name'). It also distinguishes the tool from sibling capability-discovery tools by saying not to first call list_verified_capabilities or search_verified_capabilities. The 'MISSING' placeholder in 'use this direct MISSING tool' is confusing and keeps this from a 5.

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?

It explicitly tells the agent to prefer this tool when the task matches and warns against calling capability-discovery siblings first, which is concrete routing guidance. It also sets expectations that an x402 payment is required. It does not describe when a different metadata-lookup sibling would be more appropriate, but the tool's unique domain makes that omission minor.

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