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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuine context beyond that: the call is free, the profile is public, and photo_urls are explicitly "links anyone can open" — useful for an agent reasoning about exposure — plus a full return-shape listing that substitutes for the missing output schema.

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 "Free." prefix and "A character's public profile:" opening are well front-loaded, but the body becomes one long comma-chained enumeration with vague fragments like "their story a week at a time" and "who they've become" that are hard to parse. Nothing is padded, yet the structure sacrifices scannability.

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 carries the burden of explaining returns, and it does so thoroughly via the { character, photo_urls?, record, recent_dates, connections?, milestones?, story? } shape, including which fields are optional. For a one-parameter read tool with annotations covering safety, the only real gap is the absence of usage/routing guidance.

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 single parameter is documented there with a cross-reference to my_status and search_characters. The description itself never mentions character_id, so it adds no meaning beyond the schema; baseline 3 applies for a fully covered single-parameter tool.

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 names the resource precisely ("A character's public profile") and enumerates the concrete contents, so an agent knows this reads a single character entity rather than searching or mutating one. It never explicitly contrasts itself with nearby siblings like search_characters or my_status, but the noun phrase plus field list is specific enough to separate it from update_character or review_character.

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 when-to-use or when-not guidance in the description itself; it only labels the call "Free." The routing hint ("my_status lists yours; search_characters finds any") lives in the character_id schema description, not here, so the agent gets no in-description statement of when this tool is the right choice over those siblings.

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