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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, but the description adds substantial behavioral context beyond them: a hard cap of 10 pages, the exact return shape, ranking being term-frequency based, the exact-phrase-first-then-split-words fallback, the meaning of the three title flags ([footnote match], [token match], [near match]), that empty results mean no page carries the words, and that a query with no Arabic words raises a tool error.

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 opening sentence front-loads the tool's identity, scope, and return contract, and every subsequent sentence carries real information. It is dense and slightly long, with the title-flag glossary and match-fallback detail sitting between the alternative-tool routing and the error note rather than in a clean order, but nothing is 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?

Although an output schema exists and return values need not be explained, the description still covers limits, ranking, fallback matching, flag meanings, and error behavior for a single-parameter read tool. Nothing an agent needs to call it correctly or interpret empty results is missing.

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 `query` parameter's description already specifies Arabic text, an example, and the 2–6 word sweet spot, so the baseline is 3. The description adds one genuinely new constraint not in the schema — that a query without Arabic words returns a tool error — but otherwise does not add syntax or matching-mode detail to the parameter itself.

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 first sentence gives a specific verb, resource, and scope: search the whole classical Islamic library across 8,594 works with no filtering, returning up to 10 {id, title, url} pages that chain into `fetch`. It explicitly positions itself as the generic one-argument entry in the search/fetch pair and names the scoped siblings that answer research questions better, so an agent can separate it from shamela_search and shamela_search_library 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?

It gives explicit routing rules: use shamela_search_library for hadith/tafsir/fiqh questions because unscoped ranking is by term frequency and a poetry anthology can outrank Sahih al-Bukhari; use shamela_search to pin books, categories, or a madhhab, match exact/diacritized phrases, or paginate; use shamela_cite with mode "printed_page" for citations. The condition that selects each alternative is stated, not implied.

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