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

Annotations already carry readOnly/idempotent/destructive=false, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: links are fetchable without login, expire after 'some hours' (call again for fresh ones), and come in two variants (Link as shown vs Media only). It stops short of error/rate-limit behavior, but this is rich for an annotation-covered read tool.

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?

Efficiently front-loads the fallback rule and the two selection modes, with no wasted preamble. The nested parentheticals make it dense, but every sentence carries information about selection or return behavior.

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?

With no output schema, the description fully covers what comes back (asset frame, active shared screen, transcript snippet, drawing-included vs media-only links, ephemeral access) and how to re-obtain links. An agent has everything needed to call and consume the result 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% and the schema descriptions for at/word/source already explain each field. The description's wording ('at' = recording time, 'word' = spoken phrase, asset vs shared-screen) largely restates that, adding scenario context rather than new syntax. Baseline 3 is appropriate when the schema does the heavy lifting.

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+resource ('the exact frame at a recording time (at) or when a word/phrase was spoken (word)') and explicitly positions itself against the sibling get_annotated_frames as the fallback. An agent can distinguish the two tools without opening either schema.

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?

Gives an explicit ordering rule ('call get_annotated_frames first; use this for a moment the comment doesn't link') plus the exact conditions that select this tool: a transcript-mentioned moment or a link named as not shown. Nothing is left to inference.

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