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

Annotations already cover the read-only/idempotent safety profile, but the description adds substantial behavioral context: the mandatory-constraint rule, ascending chain order (chain[0] is the Companion, last is the collector), what each result contains (book, page, resolved names and death years), and the response_format character-budget tradeoff.

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 resource and scope, then constraints, then examples. Dense and mostly waste-free, though the single long paragraph packs a lot and could be slightly tighter; every clause still carries substantive information.

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?

With no output schema, the description compensates by describing exactly what results include (book, page, resolved chain with names and death years) and how to verify them. It covers the constraint requirement, ordering, examples, and output-format behavior, leaving no significant gap for calling the tool correctly.

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%, so baseline is 3. The description adds value beyond the schema by giving worked examples (transmission:[[1580,2779]], contains:[2779] with scope_book_ids) and emphasizing the ordering/adjacency semantics and the capability requirement for response_format='none'.

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 (search isnād chains) with concrete scope: 45,220 chains across ten named ḥadīth books. It clearly differentiates itself from siblings like shamela_search_narrators (source of the ids) and shamela_get_page (for verifying against the printed page).

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 explains when to use each constraint: `contains` for narrators anywhere in the chain, `transmission` for adjacent teacher→student pairs, and notes `transmission` is the strictly stronger claim. It also states 'At least one constraint is required' and routes the agent to shamela_search_narrators for ids and shamela_get_page for verification.

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