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

Annotations only declare readOnlyHint=false, destructiveHint=false, openWorldHint=false. The description adds the non-obvious behavior that this call is free and produces nothing until run_content_plan with confirm true, plus the UI outcome ('the plan card shows the table and a Confirm button'). That is real behavioral context beyond the structured fields.

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?

Front-loads the purpose before the cost/confirm caveat and the input guidance, so the most important facts come first. The middle sentence is dense with parenthetical asides, but every clause carries actionable information.

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 17-parameter tool with an output schema and partial annotation coverage, the description covers what the call does, its cost/confirmation lifecycle, and the required conceptual inputs. Return values are correctly left to the output schema, though it says nothing about the many optional tuning params (mood, purpose, duration, music).

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?

With 100% schema coverage the baseline is 3, but the description goes further: it explains the influencer id-or-name duality, the app's optionality when on file, and groups the three mutually substitutable footage inputs (recording_upload, recording_file, app_video_url) by deferring to make_video. It omits mood/purpose/clips/hooks_per_clip, but those are fully documented in the schema.

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?

Opens with a concrete verb and resource: 'Lay out up to 30 days of posts for one app with one AI influencer,' and enumerates the plan's contents (reactions, hooks, order, footage, pricing). It is unambiguously distinct from siblings like run_content_plan (which executes the plan) and make_video (whose footage inputs it borrows).

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?

States the key gating condition explicitly: 'Free: nothing is made until run_content_plan with confirm true,' which tells the agent exactly when this tool is the right call versus the execution tool. It also gives conditional input guidance ('or nothing when it is on file from first_videos') and references make_video for footage semantics.

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