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

With no annotations, the description carries the full burden, and it does disclose two useful traits: the 'PRO' gate (subscriber tier) and that data is 'Live' (real-time). However it does not say what happens without a valid token, whether results are cached, or how errors surface.

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 compact sentences, front-loaded with the core purpose and followed by the fields returned. The leading 'PRO.' token is terse to the point of being cryptic but does not waste space.

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 two-parameter lookup with no output schema, enumerating the returned fields is valuable context. Still missing are how to obtain a protocol id, what the PRO gate means operationally, and failure behavior, which leaves gaps for an agent to call it confidently.

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 50%: access_token is documented in the schema but protocol_id is bare. The description only restates that a protocol id is the key and does not clarify its format, source (e.g. from trial_search), or behavior for invalid ids, so it only partially compensates for the undocumented 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 ('Live detail for a protocol id') and lists the returnable fields (sponsor/manufacturer, drug products, study population). The word 'detail' implicitly contrasts with the sibling 'trial_search' tools, though no sibling is named explicitly.

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?

There is no explicit when-to-use guidance or reference to alternatives like trial_search or trial_search_full. At best it is implied that you must already hold a protocol id (presumably from a search), but the description never says so or explains prerequisites.

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