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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond that: the per-result payload shape (service + plan options), the paging contract (total/limit/offset/returned with the concrete offset+=limit pattern), and the note that this endpoint lists service_option_id while the accountless x402 channel is on. Missing only rate/quota details, which are minor here.

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 decision cue ('START HERE') and organized body-then-workflow. The single dense paragraph packs several ideas (routing, payload, pagination, next step) without wasted sentences, though it runs long and could be split for scanability.

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?

No output schema exists, and the description compensates by enumerating the exact fields returned for services and their plan options, plus the pagination fields. Combined with the full parameter schema, an agent has enough to call and consume this 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 a baseline of 3 applies, but the description adds intent-mapping guidance not in the schema: 'map the user's natural-language intent (budget, country, speed) onto the structured filters below', which ties budget/speed/geo requests to min_price/max_price/speed_tier/country. That is genuine semantic value on top of the schema.

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?

Specific verb+resource ('Searches the sellable social growth service catalog') with explicit scope (Telegram, Instagram, TikTok, YouTube). It explicitly distinguishes itself from the two closest siblings, get_service and recommend_service, by naming the exact situation each covers.

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?

Opens with 'START HERE when you do not yet know which service to buy' and gives a precise routing rule for both alternatives: 'Already have a service id? get_service...' and 'Know the service and only need the right plan? recommend_service...'. It also tells the agent what to do with results (present plans, pass service_option_id to get_quote/create_paid_order) rather than defaulting to the cheapest.

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