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

Goes well beyond the readOnly/idempotent/openWorld annotations: one fresh uncached read, 12-second default deadline, no automatic retry, no API key or login, 60 requests/IP/minute, honor Retry-After on 429, and explicit failure behavior (isError/text rather than an empty journal or guessed progress). No pagination and local filtering are also disclosed.

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 purpose sentence followed by tight bullets grouped by concern (identity, encoding, selectors, errors, network behavior). Dense but nearly every line carries an operational fact; minor bloat in the closing 'no Jev, API key, login or game changes' line.

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?

Output schema exists, so return values need not be described; everything else an agent needs — identity semantics, encoding, absence of pagination/selectors, error modes, caching, timeout, rate limits — is covered.

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 single param is already documented as 'Exact RS3 player display name', so the baseline is 3. The description adds real meaning beyond the schema: it is not a Jagex login, account ID or quest name, there is no signed-in-player default, and the caller must send a raw space rather than a percent-encoded name because the server encodes once and echoes the input.

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 specific verb and resource: 'Read a public RS3 character's complete RuneMetrics quest journal.' The scope word 'complete' and the source 'RuneMetrics' immediately distinguish it from get_player_stats and get_wiki_entity_facts.

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?

Explicitly routes three siblings: recommend_next_activity for paid advice, get_player_stats for levels, get_wiki_entity_facts with kind=quest for single-quest metadata. This is the when-to-use-this-vs-alternatives pattern done properly.

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