list_characters

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety and scope are covered structurally. The description adds ordering behavior and the exact per-line content, which is genuinely useful context beyond the annotations. It doesn't discuss pagination or what happens with zero characters, so it stops short of a 5.

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-loaded with the verb, resource and ordering before any procedural instruction. The second sentence is long and enumerates return-field details that partially duplicate the existing output schema, but every clause remains informative and there is no filler.

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 zero-parameter, read-only list tool with an output schema and full annotation coverage, the description supplies everything an agent needs: when to call it, ordering, and why the call matters to the session. Return-value explanation is a bonus rather than a necessity here.

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 tool takes zero parameters, so there are no per-argument semantics to explain and the baseline of 4 applies. Nothing in the description misrepresents the empty input surface.

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 ('List the player's WoW characters') plus ordering semantics ('most recently played first') and the intent behind it ('to choose from'). An agent can distinguish it from siblings like character_status or progress_summary without opening any 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 trigger point ('at the start of every coaching session, before anything else') and the downstream purpose (choosing a character or creating a new one). No alternative tool is named, but the sequencing instruction is unambiguous enough that ambiguity is not a practical risk.

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