_get_media_data

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

Annotations already declare readOnlyHint=true, establishing the safety profile. The description adds valuable behavioral context by specifying that data is fetched in base64-encoded chunks, which goes beyond the annotation. It does not detail chunking mechanics or offset semantics, but this is acceptable for an internal tool explicitly not meant for direct use.

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 two sentences, front-loaded with the core purpose, and every word earns its place. It is highly concise without sacrificing necessary guidance on usage.

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?

Given that this is an internal tool with a clear directive to use view_media instead, the description conveys enough to prevent misuse. However, it lacks parameter documentation and any return structure information, making it incomplete for scenarios where an agent might need to understand the tool in detail (e.g., debugging). The strong guidance to avoid direct use mitigates this, justifying a mid-range score.

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 description coverage at 0%, the description was expected to compensate by explaining parameters. It mentions 'chunks' and 'base64-encoded', weakly implying chunk_size and offset, but does not explicitly define any of the four parameters (offset, filename, chunk_size, media_type). This leaves the agent without sufficient understanding of required inputs.

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 tool's function: 'fetch base64-encoded chunks of media data'. It identifies the specific resource (media data) and the output format (base64 chunks), and explicitly distinguishes itself as an internal tool from the sibling tool 'view_media' which serves as the public interface.

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 provides explicit usage guidance: 'Do not call directly — use view_media instead.' This tells the agent when not to use the tool and directs them to the correct alternative, fully satisfying the dimension.

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