Get character state

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds meaningful behavioral context by disclosing the external API source and the poe.ninja fallback path, which is beyond what annotations provide. It does not detail failure modes or auth prerequisites, but the core behavior is transparent.

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 one sentence that packs the resource, fields, source, and fallback rule without filler. Important details are front-loaded, and every clause earns its place.

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 one-parameter, read-only lookup, the description covers what is fetched, from where, and when the fallback applies. The absence of an output schema is partially mitigated by naming the returned fields. Exact response shape and error behavior are not disclosed, but the tool is simple enough that this is a minor 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?

The single parameter characterName is fully described in the schema as exact and case-sensitive. The description's phrase 'exact named character' reinforces that but does not add new semantic detail beyond the schema. Baseline 3 is appropriate given 100% schema coverage.

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 uses a specific verb ('Fetch a snapshot') and names the exact resource fields (level, class, experience, league). It also identifies the data source (GGG API with poe.ninja fallback), which clearly distinguishes it from siblings like list_characters or get_current_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?

The description implies this tool is for retrieving a specific named character from an external source, but it never explicitly states when to use this over get_current_character or list_characters. The fallback condition ('when an account is configured') provides some context, but no explicit when-to-use or when-not-to-use guidance is given.

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