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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered and the description correctly avoids restating it. What it adds is return-shape detail (grouped by length, common words first, scores per word, best and longest words, page link), but an output schema exists, so much of that is duplicative rather than new behavioral context. It says nothing about result-count caps or how the cursor pagination behaves in practice.

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 purpose is front-loaded in the first clause, before filters and return shape, which is the right ordering for scanning. It is a single dense sentence with no filler, though the long trailing enumeration of return fields makes it slightly breathless rather than crisp.

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 an 8-parameter read-only lookup with full schema coverage, an output schema, and complete annotations, the description supplies adequate context: what it does, which filters exist, and roughly what comes back. The remaining gaps are modest — no result-limit guidance and no mention of the offensive-word toggle — and are largely recoverable from the schema and output schema.

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%, so every parameter is already documented in structured form, which sets the baseline at 3. The description echoes the filter set (start, end, contains, length) and blank-tile convention without adding syntax, constraints, or interaction rules beyond the schema. It does not mention include_offensive at all, missing a chance to add value on the one behaviorally sensitive parameter.

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 opens with a specific verb and resource: 'Finds every dictionary word that can be made from a rack of letters,' then enumerates the filter dimensions. That is far more precise than a restated title. It stops short of a 5 because it never distinguishes itself from the sibling find_anagrams, which an agent could easily confuse with this subset-generation tool.

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?

Usage is only implied: the mention of a 'rack of letters,' blank tiles, and Scrabble/Words With Friends scoring signals a word-game solving context. There is no explicit when-to-use statement, no when-not-to-use, and no named alternative among find_anagrams, solve_pattern, word_list, or score_word. An agent must infer the selection rule from the parameter list alone.

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