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

Annotations already indicate the tool is not read-only and not destructive. The description adds valuable context: server-side processing, safety for any client, and the return of media_id and read_url. It does not contradict annotations.

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 description is four sentences long, each serving a distinct purpose: stating the core function, recommending usage, explaining parameter options, and describing return values. No unnecessary words.

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?

The description covers the main use case and return values, but given the complexity of 11 parameters (including nested objects and required idempotency_key), it omits explanation of the catch-all parameters body and query, and the purpose of idempotency_key. The schema fills some gaps, but more context would improve completeness.

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?

With schema coverage at 64%, the description adds significant meaning beyond the schema by explaining the trade-offs between source_url, data_url, and file_base64, and specifying that content_type is required for inline inputs. However, the required idempotency_key and catch-all parameters body/query are not elaborated.

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 clearly states the verb ('upload media') and resource ('image-attach path'), and distinguishes itself from siblings by emphasizing 'one step' and 'server-side' without client-to-Supabase connection, indicating a direct upload method.

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?

The description explicitly recommends this tool for browser-based chat clients and provides guidance on when to use each media input method (source_url for non-trivial, file_base64 for small inline images). It does not explicitly mention alternatives like aidelly_create_media_upload_url, but the context implies differentiation.

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